Hi Frank,
I am pleased that you reintroduced the 33 year calendar cycle that resolves the
difference to range of 24 hours. Thanks for introducing the concept to us some
years ago at a BSS conference. There you mentioned the idea of God's longitude,
the longitude where the spring equinox would always be on the same day if you
used the mode 33 calendar. This idea we extended in a presentation "God's
Longitude" at the NASS conference in Virginia in 2006. The presentation is
available on my website www.walkingshadows.info #7 in the list of publications
in the link Walking Shadows (Sundials). The specific link to download the 7 MB
ppt file is http://www.walkingshadow.info/Publications/GodsLongitude.ppt
You will note the use of your concept of blob charts here calculated and
plotted with spreadsheets to show the Julian, Gregorian and Khayyam/Dee
corrections.
The bottom line is Washington DC is centered on God's Longitude, 77° West. This
will change with precession among other factors inappropriate for discussion on
this mailing list.
Again on this mailing list a simple question on a solar calendar opened our
minds to some profound astronomical concepts. Lunar calendars are a whole
other irrational theme.
Regards,
Roger Bailey
--------------------------------------------------
From: "Frank King" <frank.k...@cl.cam.ac.uk>
Sent: Wednesday, March 09, 2011 10:54 AM
To: "Andrew James" <andrew.ja...@securetogether.co.uk>
Cc: "Sundial List" <sund...@rrz.uni-koeln.de>
Subject: Re: Leap Year
> Dear Andrew,
>
> Thank you for your two messages, sent off-list but my
> response may be of trifling interest to others...
>
> It is true that 128 tropical years is very close
> to 46751 days but when it comes to a real solar
> calendar (one you can look at and say "Oh, I see
> that today is 9 March") I regard this fact as a
> red herring.
>
> It is also very dubious long term. The simple
> question: "How many days are there in a tropical
> year?" has no useful answer beyond about three
> decimal places. The awkward fact is that neither
> the length of the year nor the length of the day
> is a constant. The length of the day changes
> in an especially horribly unpredictable manner
> which is why leap seconds are unpredictable.
>
>> I don't see where 36 fits in...
>
> This is a purely practical matter. If you sketch
> in my lines for, say, 12 noon on 1 March and
> 12 noon on 2 March each year for a number of
> years you will find that you are scribbling in
> two patches.
>
> The patches gradually fill in (unless you have
> a VERY sharp pencil) and expand.
>
> After 36 years you find that adjacent patches
> collide. They run into each other. In the
> region of overlap, you cannot tell whether the
> shadow refers to 1 March or 2 March. Your
> instrument is at the end of its design life
> and you have to redraw it for the next 36 years.
>
> Life becomes impossibly difficult around 2100
> because of the omitted leap year then and the
> best thing you can do is redraw your instrument
> for the 36 years from 1 March 2103. My ghost
> will be lurking around to check that you get
> it right.
>
>> I also see that 33 tropical years is just
>> 11 and a bit minutes short of a whole number
>> (12053) of days. Is this connected?
>
> Yes. Now you are really getting somewhere and
> I am starting to salivate at the prospect of
> writing a juicy reply :-)
>
>> I seem to remember there are or were various
>> calendar proposals based on 33 year cycles...
>
> Yes. Such a calendar was devised by Omar Khayyam
> (and others) in 1079. This was and still would
> be an absolutely super calendar, MUCH better
> than the horrid muddle we have to live with!
>
> A 33-year cycle which includes 8 leap years
> would be perfect if the length of year was
> 365 plus 8/33 days and it jolly nearly is.
>
> You still get very long term drift and you
> cannot win against the unpredictability
> of the length of the day but, with such a
> calendar, my patches start colliding after more
> like 500 years rather than a miserable 36.
>
> Pope Gregory missed a trick. By 1582 the
> 33-year calendar had been known about for
> over 500 years. Moreover, Pope Gregory's
> Commission included Na'amat Allah an
> eastern patriarch who would certainly
> have known about the 33-year calendar.
>
> If I could do only one thing as Dictator
> Of The World it would be to introduce
> Omar Khayyam's calendar.
>
> Vote for me!
>
> All the best
>
> Frank
>
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